Hippos Know Strangers’ and Friends’ Wheeze-Honk

Hippos Know Strangers’ and Friends’ Wheeze-Honk

Hippos Know Strangers’ and Friends’ Wheeze-Honk

In a recent study, researchers discovered that hippos recognize the sounds of other hippos and react less violently to familiar animals than to absolute strangers.

Essentially, the most frequent hippopotamus cry is a wheeze followed by a honking sound pattern. It is common for the gigantic herbivores to communicate with one another via a variety of sounds that may be heard from great distances.




Researchers have discovered that when they hear those distinctive cries from an unfamiliar species, they would respond quite differently.

“Hippopotamuses have a lot to say. ” Several different sorts of calls may be heard in their vocal repertoire. As corresponding author Nicolas Mathevon of the University of Saint-Etienne in France explains to Treehugger, “the respective importance of these calls is not yet fully known.”



“Because they create social groupings in which people communicate with one another, they need an effective communication system.” Unquestionably, the auditory channel is important.



Bioacoustics is the study of how animals interact with one another via sound. Mathevon is a bioacoustician, which means he examines the noises that animals make.



A issue that interests me is the way that sound signals might influence social interactions. Hippos are particularly interesting in this regard since they establish social groups that include both men and females, as well as young people. A number of groups (or pods) may coexist on a single lake, according to Mathevon.



In the case of hippopotamuses, no one has previously investigated the significance of audio communication during interactions within and between groups.” We were immediately faced with the issue of whether they could be distinguished by their voices when we chose to investigate them.



Friends and complete strangers should be listened to

Studying hippos may be difficult due to the difficulty in locating them in the field, identifying them, and marking individual individuals. The Maputo Special Reserve, a wildlife reserve in Mozambique that has multiple lakes where hippos may be seen, was chosen as the location for the researchers’ investigation.




The cries of each hippo group were initially recorded by the scientists. Once the recordings were made, they played them again for all of the hippo groups, seeing how they reacted to familiar sounds from their own group, nearby calls from groups in the same lake, and alien calls from a more distant group.



Each call elicited a varied reaction from the animals, which ranged from barking to approaching the noises and/or spraying excrement. According on whether the cries were from hippos they were familiar with or unknown to them, the replies were very different.



Hippos responded more strongly to unknown calls when they were played back through loudspeakers, according to Mathevon, who says they vocalized more, came closer to the loudspeaker (not all individuals, but mostly the biggest ones) and frequently exhibited marking behavior (which in hippos consists of spraying dung all over the place with their short tail).



The early trials were conducted with little knowledge of what was to come. We weren’t too shocked since other territorial species, such as numerous songbirds, respond differently to unknown and familiar vocalizations (e.g., territorial neighbors vs stranger people). “



In the journal Current Biology, the researchers reported their findings.

Conservatism is essential.
During the day, hippos congregate in great numbers in the water to drink. However, Mathevon claims that the research findings demonstrate that they are paying great attention to their surroundings, despite the fact that they seem to be doing nothing. A recording from an unfamiliar group elicited an instant response from them.

In addition to being useful for study, he believes they may also be beneficial for conservation efforts.




When it comes to relocating persons, we believe these results will serve as an inspiration for conservationists. According to Mathevon, it may be able to acclimatize the local hippos to the incoming ones’ sound before they arrive (and vice versa).



I’m not claiming that this technique will be adequate to suppress all violence since other sensory signals (chemical and visual) are almost probably also involved, but it may be beneficial in certain instances.

Unlike domesticated hippos, wild hippos make a lot of noise, and their cries may be heard for miles across lakes and rivers.

However, the exact purpose of the loud “wheeze honks” that the animals emit has been a mystery until recently.

Scientists researching hippos in an African nature reserve believe the characteristic honks of the huge creatures allow them to distinguish between friends and foes.

Furthermore, the researchers believe that the animals may recognize persons based on their “voices.”



Prof Nicolas Mathevon of the University of Saint-Etienne in France is the study’s principal investigator. He has investigated the noises made by creatures all across the globe, from leopard seals to hyenas.

While hippos have a diverse vocal repertoire that includes grunts, bellows, squeals, and “wheeze honks,” he says little is known about how they communicate with one another in social situations.



It is possible for them to recognize one other since their voices are similar. “In their call, there is information about the identity of the person — therefore they have ‘voices,'” he said. “This capacity to recognize others contributes to the development of social interactions between people.”

The noises of hippos residing in the Maputo Special Reserve in Mozambique were captured by French researchers in order to learn more about how they communicate with one another.




According to the research, the wheeze-honk is the most frequent and loudest hippo sound, and it may be heard as far as one kilometer away.

The wheeze-honks of hippos were recorded by the scientists and broadcast from the shores of lakes to examine how other individuals reacted.




They discovered that hippos could distinguish between friends, neighbors, and strangers based on their vocalizations. According to the researchers, in addition to distinguishing between friend and foe (or, at the very least, unfamiliar hippos), the animals are also likely to be able to identify between individuals – though they cannot be positive of this at this time.



Moreover, despite the fact that they seemed to be lazing on the lake, the enormous creatures were definitely paying great attention to their surroundings and reacted swiftly to the transmissions.

Unknown hippos elicited a more hostile response from the animals, which included faster, louder, and more frequent shouts, which were often accompanied by territorial displays of dung spraying.




Prof. Mathevon said that it was critical to study more about the biology and behavior of hippos in order to prevent human-animal conflicts in the future.

He believes that the information might also be useful in conservation efforts, since wild hippos are frequently relocated from one site to another in order to maintain the health of local populations.

Conservationists may be influenced by the effort to create recordings to enable local hippos to get acclimated to the sound of the new hippos before they arrive, he said further.




Hippos are not yet considered endangered in the wild, although their numbers are rapidly diminishing in captivity. Hippos are a cause of animal-human conflict, with hippos being responsible for hundreds of human fatalities each year on the African continent.